source3/lib/substitute.c

   1 /*
   2    Unix SMB/CIFS implementation.
   3    string substitution functions
   4    Copyright (C) Andrew Tridgell 1992-2000
   5    Copyright (C) Gerald Carter   2006
   6
   7    This program is free software; you can redistribute it and/or modify
   8    it under the terms of the GNU General Public License as published by
   9    the Free Software Foundation; either version 3 of the License, or
  10    (at your option) any later version.
  11
  12    This program is distributed in the hope that it will be useful,
  13    but WITHOUT ANY WARRANTY; without even the implied warranty of
  14    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  15    GNU General Public License for more details.
  16
  17    You should have received a copy of the GNU General Public License
  18    along with this program.  If not, see <http://www.gnu.org/licenses/>.
  19 */
  20
  21
  22 #include "includes.h"
  23
  24 static char *alloc_sub_basic(const char *smb_name, const char *domain_name,
  25                              const char *str);
  26
  27 userdom_struct current_user_info;
  28 fstring remote_proto="UNKNOWN";
  29
  30 /**
  31  * Set the 'local' machine name
  32  * @param local_name the name we are being called
  33  * @param if this is the 'final' name for us, not be be changed again
  34  */
  35
  36 static char *local_machine;
  37
  38 void free_local_machine_name(void)
  39 {
  40         SAFE_FREE(local_machine);
  41 }
  42
  43 bool set_local_machine_name(const char *local_name, bool perm)
  44 {
  45         static bool already_perm = false;
  46         char *tmp_local_machine = NULL;
  47         char addr[INET6_ADDRSTRLEN];
  48         size_t len;
  49
  50         tmp_local_machine = SMB_STRDUP(local_name);
  51         if (!tmp_local_machine) {
  52                 return false;
  53         }
  54         trim_char(tmp_local_machine,' ',' ');
  55
  56         /*
  57          * Windows NT/2k uses "*SMBSERVER" and XP uses "*SMBSERV"
  58          * arrggg!!!
  59          */
  60
  61         if (strequal(tmp_local_machine, "*SMBSERVER") ||
  62                         strequal(tmp_local_machine, "*SMBSERV") )  {
  63                 SAFE_FREE(local_machine);
  64                 local_machine = SMB_STRDUP(client_socket_addr(get_client_fd(),
  65                                         addr, sizeof(addr)) );
  66                 SAFE_FREE(tmp_local_machine);
  67                 return local_machine ? true : false;
  68         }
  69
  70         if (already_perm) {
  71                 return true;
  72         }
  73
  74         SAFE_FREE(local_machine);
  75         len = strlen(tmp_local_machine);
  76         local_machine = SMB_CALLOC_ARRAY(char, len+1);
  77         if (!local_machine) {
  78                 SAFE_FREE(tmp_local_machine);
  79                 return false;
  80         }
  81         /* alpha_strcpy includes the space for the terminating nul. */
  82         alpha_strcpy(local_machine,tmp_local_machine,
  83                         SAFE_NETBIOS_CHARS,len+1);
  84         strlower_m(local_machine);
  85         SAFE_FREE(tmp_local_machine);
  86
  87         already_perm = perm;
  88
  89         return true;
  90 }
  91
  92 const char *get_local_machine_name(void)
  93 {
  94         if (!local_machine || !*local_machine) {
  95                 return global_myname();
  96         }
  97
  98         return local_machine;
  99 }
 100
 101 /**
 102  * Set the 'remote' machine name
 103  * @param remote_name the name our client wants to be called by
 104  * @param if this is the 'final' name for them, not be be changed again
 105  */
 106
 107 static char *remote_machine;
 108
 109 bool set_remote_machine_name(const char *remote_name, bool perm)
 110 {
 111         static bool already_perm = False;
 112         char *tmp_remote_machine;
 113         size_t len;
 114
 115         if (already_perm) {
 116                 return true;
 117         }
 118
 119         tmp_remote_machine = SMB_STRDUP(remote_name);
 120         if (!tmp_remote_machine) {
 121                 return false;
 122         }
 123         trim_char(tmp_remote_machine,' ',' ');
 124
 125         SAFE_FREE(remote_machine);
 126         len = strlen(tmp_remote_machine);
 127         remote_machine = SMB_CALLOC_ARRAY(char, len+1);
 128         if (!remote_machine) {
 129                 SAFE_FREE(tmp_remote_machine);
 130                 return false;
 131         }
 132
 133         /* alpha_strcpy includes the space for the terminating nul. */
 134         alpha_strcpy(remote_machine,tmp_remote_machine,
 135                         SAFE_NETBIOS_CHARS,len+1);
 136         strlower_m(remote_machine);
 137         SAFE_FREE(tmp_remote_machine);
 138
 139         already_perm = perm;
 140
 141         return true;
 142 }
 143
 144 const char *get_remote_machine_name(void)
 145 {
 146         return remote_machine ? remote_machine : "";
 147 }
 148
 149 /*******************************************************************
 150  Setup the string used by %U substitution.
 151 ********************************************************************/
 152
 153 static char *smb_user_name;
 154
 155 void sub_set_smb_name(const char *name)
 156 {
 157         char *tmp;
 158         size_t len;
 159         bool is_machine_account = false;
 160
 161         /* don't let anonymous logins override the name */
 162         if (!name || !*name) {
 163                 return;
 164         }
 165
 166         tmp = SMB_STRDUP(name);
 167         if (!tmp) {
 168                 return;
 169         }
 170         trim_char(tmp, ' ', ' ');
 171         strlower_m(tmp);
 172
 173         len = strlen(tmp);
 174
 175         if (len == 0) {
 176                 SAFE_FREE(tmp);
 177                 return;
 178         }
 179
 180         /* long story but here goes....we have to allow usernames
 181            ending in '$' as they are valid machine account names.
 182            So check for a machine account and re-add the '$'
 183            at the end after the call to alpha_strcpy().   --jerry  */
 184
 185         if (tmp[len-1] == '$') {
 186                 is_machine_account = True;
 187         }
 188
 189         SAFE_FREE(smb_user_name);
 190         smb_user_name = SMB_CALLOC_ARRAY(char, len+1);
 191         if (!smb_user_name) {
 192                 SAFE_FREE(tmp);
 193                 return;
 194         }
 195
 196         /* alpha_strcpy includes the space for the terminating nul. */
 197         alpha_strcpy(smb_user_name, tmp,
 198                         SAFE_NETBIOS_CHARS,
 199                         len+1);
 200
 201         SAFE_FREE(tmp);
 202
 203         if (is_machine_account) {
 204                 len = strlen(smb_user_name);
 205                 smb_user_name[len-1] = '$';
 206         }
 207 }
 208
 209 static const char *get_smb_user_name(void)
 210 {
 211         return smb_user_name ? smb_user_name : "";
 212 }
 213
 214 /*******************************************************************
 215  Setup the strings used by substitutions. Called per packet. Ensure
 216  %U name is set correctly also.
 217
 218  smb_name must be sanitized by alpha_strcpy
 219 ********************************************************************/
 220
 221 void set_current_user_info(const char *smb_name, const char *unix_name,
 222                            const char *domain)
 223 {
 224         fstrcpy(current_user_info.smb_name, smb_name);
 225         fstrcpy(current_user_info.unix_name, unix_name);
 226         fstrcpy(current_user_info.domain, domain);
 227
 228         /* The following is safe as current_user_info.smb_name
 229          * has already been sanitised in register_existing_vuid. */
 230
 231         sub_set_smb_name(current_user_info.smb_name);
 232 }
 233
 234 /*******************************************************************
 235  Return the current active user name.
 236 *******************************************************************/
 237
 238 const char *get_current_username(void)
 239 {
 240         if (current_user_info.smb_name[0] == '\0' ) {
 241                 return get_smb_user_name();
 242         }
 243
 244         return current_user_info.smb_name;
 245 }
 246
 247 /*******************************************************************
 248  Given a pointer to a %$(NAME) in p and the whole string in str
 249  expand it as an environment variable.
 250  Return a new allocated and expanded string.
 251  Based on code by Branko Cibej <branko.cibej@hermes.si>
 252  When this is called p points at the '%' character.
 253  May substitute multiple occurrencies of the same env var.
 254 ********************************************************************/
 255
 256 static char * realloc_expand_env_var(char *str, char *p)
 257 {
 258         char *envname;
 259         char *envval;
 260         char *q, *r;
 261         int copylen;
 262
 263         if (p[0] != '%' || p[1] != '$' || p[2] != '(') {
 264                 return str;
 265         }
 266
 267         /*
 268          * Look for the terminating ')'.
 269          */
 270
 271         if ((q = strchr_m(p,')')) == NULL) {
 272                 DEBUG(0,("expand_env_var: Unterminated environment variable [%s]\n", p));
 273                 return str;
 274         }
 275
 276         /*
 277          * Extract the name from within the %$(NAME) string.
 278          */
 279
 280         r = p + 3;
 281         copylen = q - r;
 282
 283         /* reserve space for use later add %$() chars */
 284         if ( (envname = (char *)SMB_MALLOC(copylen + 1 + 4)) == NULL ) {
 285                 return NULL;
 286         }
 287
 288         strncpy(envname,r,copylen);
 289         envname[copylen] = '\0';
 290
 291         if ((envval = getenv(envname)) == NULL) {
 292                 DEBUG(0,("expand_env_var: Environment variable [%s] not set\n", envname));
 293                 SAFE_FREE(envname);
 294                 return str;
 295         }
 296
 297         /*
 298          * Copy the full %$(NAME) into envname so it
 299          * can be replaced.
 300          */
 301
 302         copylen = q + 1 - p;
 303         strncpy(envname,p,copylen);
 304         envname[copylen] = '\0';
 305         r = realloc_string_sub(str, envname, envval);
 306         SAFE_FREE(envname);
 307
 308         return r;
 309 }
 310
 311 /*******************************************************************
 312 *******************************************************************/
 313
 314 static char *longvar_domainsid( void )
 315 {
 316         DOM_SID sid;
 317         fstring tmp;
 318         char *sid_string;
 319
 320         if ( !secrets_fetch_domain_sid( lp_workgroup(), &sid ) ) {
 321                 return NULL;
 322         }
 323
 324         sid_string = SMB_STRDUP( sid_to_fstring( tmp, &sid ) );
 325
 326         if ( !sid_string ) {
 327                 DEBUG(0,("longvar_domainsid: failed to dup SID string!\n"));
 328         }
 329
 330         return sid_string;
 331 }
 332
 333 /*******************************************************************
 334 *******************************************************************/
 335
 336 struct api_longvar {
 337         const char *name;
 338         char* (*fn)( void );
 339 };
 340
 341 static struct api_longvar longvar_table[] = {
 342         { "DomainSID",          longvar_domainsid },
 343         { NULL,                 NULL }
 344 };
 345
 346 static char *get_longvar_val( const char *varname )
 347 {
 348         int i;
 349
 350         DEBUG(7,("get_longvar_val: expanding variable [%s]\n", varname));
 351
 352         for ( i=0; longvar_table[i].name; i++ ) {
 353                 if ( strequal( longvar_table[i].name, varname ) ) {
 354                         return longvar_table[i].fn();
 355                 }
 356         }
 357
 358         return NULL;
 359 }
 360
 361 /*******************************************************************
 362  Expand the long smb.conf variable names given a pointer to a %(NAME).
 363  Return the number of characters by which the pointer should be advanced.
 364  When this is called p points at the '%' character.
 365 ********************************************************************/
 366
 367 static char *realloc_expand_longvar(char *str, char *p)
 368 {
 369         fstring varname;
 370         char *value;
 371         char *q, *r;
 372         int copylen;
 373
 374         if ( p[0] != '%' || p[1] != '(' ) {
 375                 return str;
 376         }
 377
 378         /* Look for the terminating ')'.*/
 379
 380         if ((q = strchr_m(p,')')) == NULL) {
 381                 DEBUG(0,("realloc_expand_longvar: Unterminated environment variable [%s]\n", p));
 382                 return str;
 383         }
 384
 385         /* Extract the name from within the %(NAME) string.*/
 386
 387         r = p+2;
 388         copylen = MIN( (q-r), (sizeof(varname)-1) );
 389         strncpy(varname, r, copylen);
 390         varname[copylen] = '\0';
 391
 392         if ((value = get_longvar_val(varname)) == NULL) {
 393                 DEBUG(0,("realloc_expand_longvar: Variable [%s] not set.  Skipping\n", varname));
 394                 return str;
 395         }
 396
 397         /* Copy the full %(NAME) into envname so it can be replaced.*/
 398
 399         copylen = MIN( (q+1-p),(sizeof(varname)-1) );
 400         strncpy( varname, p, copylen );
 401         varname[copylen] = '\0';
 402         r = realloc_string_sub(str, varname, value);
 403         SAFE_FREE( value );
 404
 405         /* skip over the %(varname) */
 406
 407         return r;
 408 }
 409
 410 /*******************************************************************
 411  Patch from jkf@soton.ac.uk
 412  Added this to implement %p (NIS auto-map version of %H)
 413 *******************************************************************/
 414
 415 static const char *automount_path(const char *user_name)
 416 {
 417         TALLOC_CTX *ctx = talloc_tos();
 418         const char *server_path;
 419
 420         /* use the passwd entry as the default */
 421         /* this will be the default if WITH_AUTOMOUNT is not used or fails */
 422
 423         server_path = talloc_strdup(ctx, get_user_home_dir(ctx, user_name));
 424         if (!server_path) {
 425                 return "";
 426         }
 427
 428 #if (defined(HAVE_NETGROUP) && defined (WITH_AUTOMOUNT))
 429
 430         if (lp_nis_home_map()) {
 431                 const char *home_path_start;
 432                 char *automount_value = automount_lookup(ctx, user_name);
 433
 434                 if(automount_value && strlen(automount_value) > 0) {
 435                         home_path_start = strchr_m(automount_value,':');
 436                         if (home_path_start != NULL) {
 437                                 DEBUG(5, ("NIS lookup succeeded. "
 438                                         "Home path is: %s\n",
 439                                         home_path_start ?
 440                                                 (home_path_start+1):""));
 441                                 server_path = talloc_strdup(ctx,
 442                                                         home_path_start+1);
 443                                 if (!server_path) {
 444                                         server_path = "";
 445                                 }
 446                         }
 447                 } else {
 448                         /* NIS key lookup failed: default to
 449                          * user home directory from password file */
 450                         DEBUG(5, ("NIS lookup failed. Using Home path from "
 451                         "passwd file. Home path is: %s\n", server_path ));
 452                 }
 453         }
 454 #endif
 455
 456         DEBUG(4,("Home server path: %s\n", server_path));
 457         return server_path;
 458 }
 459
 460 /*******************************************************************
 461  Patch from jkf@soton.ac.uk
 462  This is Luke's original function with the NIS lookup code
 463  moved out to a separate function.
 464 *******************************************************************/
 465
 466 static const char *automount_server(const char *user_name)
 467 {
 468         TALLOC_CTX *ctx = talloc_tos();
 469         const char *server_name;
 470         const char *local_machine_name = get_local_machine_name();
 471
 472         /* use the local machine name as the default */
 473         /* this will be the default if WITH_AUTOMOUNT is not used or fails */
 474         if (local_machine_name && *local_machine_name) {
 475                 server_name = talloc_strdup(ctx, local_machine_name);
 476         } else {
 477                 server_name = talloc_strdup(ctx, global_myname());
 478         }
 479
 480         if (!server_name) {
 481                 return "";
 482         }
 483
 484 #if (defined(HAVE_NETGROUP) && defined (WITH_AUTOMOUNT))
 485         if (lp_nis_home_map()) {
 486                 char *p;
 487                 char *srv;
 488                 char *automount_value = automount_lookup(ctx, user_name);
 489                 if (!automount_value) {
 490                         return "";
 491                 }
 492                 srv = talloc_strdup(ctx, automount_value);
 493                 if (!srv) {
 494                         return "";
 495                 }
 496                 p = strchr_m(srv, ':');
 497                 if (!p) {
 498                         return "";
 499                 }
 500                 *p = '\0';
 501                 server_name = srv;
 502                 DEBUG(5, ("NIS lookup succeeded.  Home server %s\n",
 503                                         server_name));
 504         }
 505 #endif
 506
 507         DEBUG(4,("Home server: %s\n", server_name));
 508         return server_name;
 509 }
 510
 511 /****************************************************************************
 512  Do some standard substitutions in a string.
 513  len is the length in bytes of the space allowed in string str. If zero means
 514  don't allow expansions.
 515 ****************************************************************************/
 516
 517 void standard_sub_basic(const char *smb_name, const char *domain_name,
 518                         char *str, size_t len)
 519 {
 520         char *s;
 521
 522         if ( (s = alloc_sub_basic( smb_name, domain_name, str )) != NULL ) {
 523                 strncpy( str, s, len );
 524         }
 525
 526         SAFE_FREE( s );
 527 }
 528
 529 /****************************************************************************
 530  Do some standard substitutions in a string.
 531  This function will return an allocated string that have to be freed.
 532 ****************************************************************************/
 533
 534 char *talloc_sub_basic(TALLOC_CTX *mem_ctx, const char *smb_name,
 535                        const char *domain_name, const char *str)
 536 {
 537         char *a, *t;
 538
 539         if ( (a = alloc_sub_basic(smb_name, domain_name, str)) == NULL ) {
 540                 return NULL;
 541         }
 542         t = talloc_strdup(mem_ctx, a);
 543         SAFE_FREE(a);
 544         return t;
 545 }
 546
 547 /****************************************************************************
 548 ****************************************************************************/
 549
 550 static char *alloc_sub_basic(const char *smb_name, const char *domain_name,
 551                              const char *str)
 552 {
 553         char *b, *p, *s, *r, *a_string;
 554         fstring pidstr, vnnstr;
 555         char addr[INET6_ADDRSTRLEN];
 556         const char *local_machine_name = get_local_machine_name();
 557         TALLOC_CTX *tmp_ctx = NULL;
 558
 559         /* workaround to prevent a crash while looking at bug #687 */
 560
 561         if (!str) {
 562                 DEBUG(0,("alloc_sub_basic: NULL source string!  This should not happen\n"));
 563                 return NULL;
 564         }
 565
 566         a_string = SMB_STRDUP(str);
 567         if (a_string == NULL) {
 568                 DEBUG(0, ("alloc_sub_basic: Out of memory!\n"));
 569                 return NULL;
 570         }
 571
 572         tmp_ctx = talloc_stackframe();
 573
 574         for (b = s = a_string; (p = strchr_m(s, '%')); s = a_string + (p - b)) {
 575
 576                 r = NULL;
 577                 b = a_string;
 578
 579                 switch (*(p+1)) {
 580                 case 'U' :
 581                         r = strlower_talloc(tmp_ctx, smb_name);
 582                         if (r == NULL) {
 583                                 goto error;
 584                         }
 585                         a_string = realloc_string_sub(a_string, "%U", r);
 586                         break;
 587                 case 'G' : {
 588                         struct passwd *pass;
 589                         r = talloc_strdup(tmp_ctx, smb_name);
 590                         if (r == NULL) {
 591                                 goto error;
 592                         }
 593                         pass = Get_Pwnam_alloc(tmp_ctx, r);
 594                         if (pass != NULL) {
 595                                 a_string = realloc_string_sub(
 596                                         a_string, "%G",
 597                                         gidtoname(pass->pw_gid));
 598                         }
 599                         TALLOC_FREE(pass);
 600                         break;
 601                 }
 602                 case 'D' :
 603                         r = strupper_talloc(tmp_ctx, domain_name);
 604                         if (r == NULL) {
 605                                 goto error;
 606                         }
 607                         a_string = realloc_string_sub(a_string, "%D", r);
 608                         break;
 609                 case 'I' : {
 610                         int offset = 0;
 611                         client_addr(get_client_fd(), addr, sizeof(addr));
 612                         if (strnequal(addr,"::ffff:",7)) {
 613                                 offset = 7;
 614                         }
 615                         a_string = realloc_string_sub(a_string, "%I",
 616                                                       addr + offset);
 617                         break;
 618                 }
 619                 case 'i':
 620                         a_string = realloc_string_sub( a_string, "%i",
 621                                         client_socket_addr(get_client_fd(), addr, sizeof(addr)) );
 622                         break;
 623                 case 'L' :
 624                         if ( StrnCaseCmp(p, "%LOGONSERVER%", strlen("%LOGONSERVER%")) == 0 ) {
 625                                 break;
 626                         }
 627                         if (local_machine_name && *local_machine_name) {
 628                                 a_string = realloc_string_sub(a_string, "%L", local_machine_name);
 629                         } else {
 630                                 a_string = realloc_string_sub(a_string, "%L", global_myname());
 631                         }
 632                         break;
 633                 case 'N':
 634                         a_string = realloc_string_sub(a_string, "%N", automount_server(smb_name));
 635                         break;
 636                 case 'M' :
 637                         a_string = realloc_string_sub(a_string, "%M", client_name(get_client_fd()));
 638                         break;
 639                 case 'R' :
 640                         a_string = realloc_string_sub(a_string, "%R", remote_proto);
 641                         break;
 642                 case 'T' :
 643                         a_string = realloc_string_sub(a_string, "%T", current_timestring(tmp_ctx, False));
 644                         break;
 645                 case 'a' :
 646                         a_string = realloc_string_sub(a_string, "%a",
 647                                         get_remote_arch_str());
 648                         break;
 649                 case 'd' :
 650                         slprintf(pidstr,sizeof(pidstr)-1, "%d",(int)sys_getpid());
 651                         a_string = realloc_string_sub(a_string, "%d", pidstr);
 652                         break;
 653                 case 'h' :
 654                         a_string = realloc_string_sub(a_string, "%h", myhostname());
 655                         break;
 656                 case 'm' :
 657                         a_string = realloc_string_sub(a_string, "%m",
 658                                                       remote_machine
 659                                                       ? remote_machine
 660                                                       : "");
 661                         break;
 662                 case 'v' :
 663                         a_string = realloc_string_sub(a_string, "%v", samba_version_string());
 664                         break;
 665                 case 'w' :
 666                         a_string = realloc_string_sub(a_string, "%w", lp_winbind_separator());
 667                         break;
 668                 case '$' :
 669                         a_string = realloc_expand_env_var(a_string, p); /* Expand environment variables */
 670                         break;
 671                 case '(':
 672                         a_string = realloc_expand_longvar( a_string, p );
 673                         break;
 674                 case 'V' :
 675                         slprintf(vnnstr,sizeof(vnnstr)-1, "%u", get_my_vnn());
 676                         a_string = realloc_string_sub(a_string, "%V", vnnstr);
 677                         break;
 678                 default:
 679                         break;
 680                 }
 681
 682                 p++;
 683                 TALLOC_FREE(r);
 684
 685                 if (a_string == NULL) {
 686                         goto done;
 687                 }
 688         }
 689
 690         goto done;
 691
 692 error:
 693         SAFE_FREE(a_string);
 694
 695 done:
 696         TALLOC_FREE(tmp_ctx);
 697         return a_string;
 698 }
 699
 700 /****************************************************************************
 701  Do some specific substitutions in a string.
 702  This function will return an allocated string that have to be freed.
 703 ****************************************************************************/
 704
 705 char *talloc_sub_specified(TALLOC_CTX *mem_ctx,
 706                         const char *input_string,
 707                         const char *username,
 708                         const char *domain,
 709                         uid_t uid,
 710                         gid_t gid)
 711 {
 712         char *a_string;
 713         char *ret_string = NULL;
 714         char *b, *p, *s;
 715         TALLOC_CTX *tmp_ctx;
 716
 717         if (!(tmp_ctx = talloc_new(mem_ctx))) {
 718                 DEBUG(0, ("talloc_new failed\n"));
 719                 return NULL;
 720         }
 721
 722         a_string = talloc_strdup(tmp_ctx, input_string);
 723         if (a_string == NULL) {
 724                 DEBUG(0, ("talloc_sub_specified: Out of memory!\n"));
 725                 goto done;
 726         }
 727
 728         for (b = s = a_string; (p = strchr_m(s, '%')); s = a_string + (p - b)) {
 729
 730                 b = a_string;
 731
 732                 switch (*(p+1)) {
 733                 case 'U' :
 734                         a_string = talloc_string_sub(
 735                                 tmp_ctx, a_string, "%U", username);
 736                         break;
 737                 case 'u' :
 738                         a_string = talloc_string_sub(
 739                                 tmp_ctx, a_string, "%u", username);
 740                         break;
 741                 case 'G' :
 742                         if (gid != -1) {
 743                                 a_string = talloc_string_sub(
 744                                         tmp_ctx, a_string, "%G",
 745                                         gidtoname(gid));
 746                         } else {
 747                                 a_string = talloc_string_sub(
 748                                         tmp_ctx, a_string,
 749                                         "%G", "NO_GROUP");
 750                         }
 751                         break;
 752                 case 'g' :
 753                         if (gid != -1) {
 754                                 a_string = talloc_string_sub(
 755                                         tmp_ctx, a_string, "%g",
 756                                         gidtoname(gid));
 757                         } else {
 758                                 a_string = talloc_string_sub(
 759                                         tmp_ctx, a_string, "%g", "NO_GROUP");
 760                         }
 761                         break;
 762                 case 'D' :
 763                         a_string = talloc_string_sub(tmp_ctx, a_string,
 764                                                      "%D", domain);
 765                         break;
 766                 case 'N' :
 767                         a_string = talloc_string_sub(
 768                                 tmp_ctx, a_string, "%N",
 769                                 automount_server(username));
 770                         break;
 771                 default:
 772                         break;
 773                 }
 774
 775                 p++;
 776                 if (a_string == NULL) {
 777                         goto done;
 778                 }
 779         }
 780
 781         /* Watch out, using "mem_ctx" here, so all intermediate stuff goes
 782          * away with the TALLOC_FREE(tmp_ctx) further down. */
 783
 784         ret_string = talloc_sub_basic(mem_ctx, username, domain, a_string);
 785
 786  done:
 787         TALLOC_FREE(tmp_ctx);
 788         return ret_string;
 789 }
 790
 791 /****************************************************************************
 792 ****************************************************************************/
 793
 794 static char *alloc_sub_advanced(const char *servicename, const char *user,
 795                          const char *connectpath, gid_t gid,
 796                          const char *smb_name, const char *domain_name,
 797                          const char *str)
 798 {
 799         char *a_string, *ret_string;
 800         char *b, *p, *s;
 801
 802         a_string = SMB_STRDUP(str);
 803         if (a_string == NULL) {
 804                 DEBUG(0, ("alloc_sub_advanced: Out of memory!\n"));
 805                 return NULL;
 806         }
 807
 808         for (b = s = a_string; (p = strchr_m(s, '%')); s = a_string + (p - b)) {
 809
 810                 b = a_string;
 811
 812                 switch (*(p+1)) {
 813                 case 'N' :
 814                         a_string = realloc_string_sub(a_string, "%N", automount_server(user));
 815                         break;
 816                 case 'H': {
 817                         char *h;
 818                         if ((h = get_user_home_dir(talloc_tos(), user)))
 819                                 a_string = realloc_string_sub(a_string, "%H", h);
 820                         TALLOC_FREE(h);
 821                         break;
 822                 }
 823                 case 'P':
 824                         a_string = realloc_string_sub(a_string, "%P", connectpath);
 825                         break;
 826                 case 'S':
 827                         a_string = realloc_string_sub(a_string, "%S", servicename);
 828                         break;
 829                 case 'g':
 830                         a_string = realloc_string_sub(a_string, "%g", gidtoname(gid));
 831                         break;
 832                 case 'u':
 833                         a_string = realloc_string_sub(a_string, "%u", user);
 834                         break;
 835
 836                         /* Patch from jkf@soton.ac.uk Left the %N (NIS
 837                          * server name) in standard_sub_basic as it is
 838                          * a feature for logon servers, hence uses the
 839                          * username.  The %p (NIS server path) code is
 840                          * here as it is used instead of the default
 841                          * "path =" string in [homes] and so needs the
 842                          * service name, not the username.  */
 843                 case 'p':
 844                         a_string = realloc_string_sub(a_string, "%p",
 845                                                       automount_path(servicename));
 846                         break;
 847
 848                 default:
 849                         break;
 850                 }
 851
 852                 p++;
 853                 if (a_string == NULL) {
 854                         return NULL;
 855                 }
 856         }
 857
 858         ret_string = alloc_sub_basic(smb_name, domain_name, a_string);
 859         SAFE_FREE(a_string);
 860         return ret_string;
 861 }
 862
 863 /*
 864  * This obviously is inefficient and needs to be merged into
 865  * alloc_sub_advanced...
 866  */
 867
 868 char *talloc_sub_advanced(TALLOC_CTX *mem_ctx,
 869                           const char *servicename, const char *user,
 870                           const char *connectpath, gid_t gid,
 871                           const char *smb_name, const char *domain_name,
 872                           const char *str)
 873 {
 874         char *a, *t;
 875
 876         if (!(a = alloc_sub_advanced(servicename, user, connectpath, gid,
 877                                      smb_name, domain_name, str))) {
 878                 return NULL;
 879         }
 880         t = talloc_strdup(mem_ctx, a);
 881         SAFE_FREE(a);
 882         return t;
 883 }
 884
 885
 886 void standard_sub_advanced(const char *servicename, const char *user,
 887                            const char *connectpath, gid_t gid,
 888                            const char *smb_name, const char *domain_name,
 889                            char *str, size_t len)
 890 {
 891         char *s;
 892
 893         s = alloc_sub_advanced(servicename, user, connectpath,
 894                                gid, smb_name, domain_name, str);
 895
 896         if ( s ) {
 897                 strncpy( str, s, len );
 898                 SAFE_FREE( s );
 899         }
 900 }
 901
 902 /****************************************************************************
 903  Do some standard substitutions in a string.
 904 ****************************************************************************/
 905
 906 char *standard_sub_conn(TALLOC_CTX *ctx, connection_struct *conn, const char *str)
 907 {
 908         return talloc_sub_advanced(ctx,
 909                                 lp_servicename(SNUM(conn)),
 910                                 conn->server_info->unix_name,
 911                                 conn->connectpath,
 912                                 conn->server_info->utok.gid,
 913                                 get_smb_user_name(),
 914                                 "",
 915                                 str);
 916 }